Dam Construction Is Set to Destroy the 'Mother of all Rivers'

The Mekong River is facing its greatest threat ever. Next week, the governments of Laos, Thailand, Cambodia and Vietnam will meet to decide whether to approve the first-ever dam planned for the lower Mekong mainstream, the Xayaburi Dam. The implications of this decision are serious and irreversible.

The Mekong River - known locally as the "Mother of all Rivers" - is the world's largest inland fishery. This fishery constitutes the primary source of protein for the majority of the basin's 60 million inhabitants, many of whom are subsistence farmers. To harm the fishery is to harm the food security of the region's poor.

Yet Mekong governments are proposing a series of 11 dams on the Mekong mainstream. These impenetrable walls would block the migration of fish and profoundly disrupt the river ecology, sounding a death knell for the Mekong's productive fisheries.

Fisheries experts agree that the Xayaburi Dam alone would threaten 41 fish species with extinction, including the iconic Mekong Giant Catfish - a fish the size of a large dolphin. A Mekong River Commission review found that the six dams proposed in this stretch of the river would result in fisheries losses equivalent to nearly half of the entire yield for the country of Laos. While the exact loss associated with the Xayaburi Dam is unknown, the review states: "Experience from other areas suggests that most of the loss would be associated with construction of the first dam in the cascade." With the majority of the basin's population dependent on the river's resources, the loss would place the livelihoods of nearly half a million people at risk.

The scientific consensus is against building Xayaburi Dam. Fisheries scientists unanimously agree that the dam's impacts on fisheries cannot be mitigated. Even though the dam builders have promised to install a fish ladder to allow for fish migration, the Mekong River Commission's own experts agree that this ladder will be ineffective and that there is no technology in existence to sufficiently mitigate the dam's impacts.

Scientists who conducted a Strategic Environmental Assessment of all 11 dams proposed for the lower Mekong agreed that the projects would be a disaster for the river and its inhabitants. They recommended a 10-year moratorium on mainstream dams after finding that the dam cascade would cut the fish catch in half, threatening the livelihoods of up to 40 million people. The reduction of the river's sediment flow would also stop the flow of important nutrients which help to fertilize Cambodia's floodplains and Great Lake system, along with the Mekong Delta in Vietnam. The "butterfly effect" of this seemingly small ecological change would affect the stability and productivity of the Mekong Delta, known as the rice bowl of Vietnam.

The decision that the four lower Mekong governments will make next week is literally a life-or-death decision for the Mekong River and its people. Will they allow this thriving and beautiful river - currently a global treasure - to be turned into a stagnant series of reservoirs with little sign of its once bountiful fisheries? Or will they recognize that the best interests of the region's people lies in maintaining a healthy Mekong River, a river that feeds millions?

Laos has said it is determined to build the project at all costs and Thailand's political leaders are noticeably silent. The current ruling party in Thailand has such close political and economic connections to the company promoting the dam, Ch. Karnchang, that it is afraid to even speak publicly about the Xayaburi Dam. That leaves Cambodia and Vietnam. Senior government officials in both Cambodia and Vietnam have expressed concern about the Xayaburi Dam and its implications for food security in the region, but will they rise above narrow political and economic interests and speak out against their neighbor's plan? Both countries want to build their own dams, but both also have a vested interest in keeping the Mekong healthy.

What's worse is that there's no evidence that the electricity from Xayaburi Dam is really needed. The project is supposed to supply electricity to Thailand, yet Thailand's electricity utility EGAT consistently overestimates future demand, and in 2010 the utility had a whopping 30% reserve margin. The Strategic Environmental Assessment found that all 11 mainstream dams would generate the equivalent of one year's increase in electricity demand for the lower Mekong Basin. Viewed in this light, the case for damming the Mekong mainstream is incredibly short-sighted.

For the sake of the Mekong River and its inhabitants, we must hope that reason prevails when the governments meet next week, and that the decision-makers look beyond their own short political lives and into a future in which a healthy, undammed Mekong continues to provide for generations to come. Their grandchildren will thank them.

Aviva Imhof is Interim Executive Director at International Rivers, an environmental and human rights organization based in Berkeley, California